PDHonline Course L118
PDHonline Course L118 (4 PDH)
Basic Public Lands
Jan Van Sickle, PLS
2012
PDH Online | PDH Center
5272 Meadow Estates Drive
Fairfax, VA22030-6658
Phone & Fax: 703-988-0088
Basic Public Lands
Jan Van Sickle, PLS
From the very beginning of the Public Land Surveying System it has always been the policy of the Federal Government that land in the public domain must be surveyed before it is sold to others, that is before it is patented. Therefore, more than 200 years ago the United States embarked on the most extensive surveying project ever undertaken under the Land Ordinance Act. The work began in Ohio in the autumn of 1785. On April 25, 1812 the Congress created the General Land Office (GLO) to survey and administer the PLSS. Under the GLO the work was done under a contract system. The contractors were Deputy Surveyors that worked for Surveyors General across the country. The surveying was not actually done by government employees until 1910. Later, the Bureau of Land Management was created in the Department of the Interior in 1946. It has been in charge of the system since.
The PLSS was and is an eminently practical attempt to cover a large portion of the curved surface of the Earth with a Cartesian grid with one-mile squares, sections. The degree to which it has succeeded can be most clearly seen when flying over the central and western United States. The orderly patchwork quality of the landscape is a testament to those who created and those who maintain the Rectangular System.
It has had a prominent place in the definition of the lands in the thirty states that were created from the public domain. These lands were acquired by purchase, treaty or cession and once amounted to over 1.8 billion acres. The majority of that land has now been laid out into sections and passed from the Federal Government into other hands, but its measurement is still, in most cases, governed by the rules of the PLSS.
The Public Land Surveying System is a huge subject. The small portion of it that will be presented here is intended to offer just a basic understanding of a few elements of the topic. Even though the application of the system can be complex, the design has always been straightforward and practical. And it is that design, as currently practiced, that will be the emphasis here.
The Initial Points
Figure 1.1
In a sense, initial points are the origins of the PLSS. They represent the intersection of
two axes. There are 32 initial points in the coterminous United States and there are 5 in Alaska. Initial points were first mentioned in the written Manuals of Instructions in 1881. There were several of these manuals. The first official version was issued by the GLO in 1851. They were the vehicles by which the Commissioner of the GLO communicated the methods of survey to the Surveyors General. They reflect the evolution of the system’s surveying procedures. However, by the time the establishment of initial points was mentioned in a manual many of the 37 in place today had already been set, nevertheless, it said,
Initial points from which the lines of the public surveys are to be extended must be established whenever necessary under such special instructions as may be prescribed by the Commissioner of the General Land Office. The locus of such initial points must be selected with great care and due consideration for their prominence and easy identification, and must be established astronomically.
(GLO 1881: 35)
In other words, they were set somewhat arbitrarily, as needed and were assigned latitudes and longitudes derived astronomically.
East and west from the initial point a Baseline was laid out. This base line was intended to follow an astronomically determined parallel of latitude. And it did so as nearly as possible with corner monuments being established every half-mile, that is every 40 chains. The chain was, and is, the native unit of the PLSS system. A Gunter’s chain is 66 feet long, and therefore, 40 chains is 2640 feet, or half a mile. It is also important to note that 10 square chains is 1 acre, a convenient relationship.
A Principal Meridian was extended north and south from the initial point following a meridian of longitude, again astronomically determined, on which corner monuments were set every half mile, every 40 chains. While the initial point and the Baseline are not usually named, it is common for the Principal Meridian to have a name such as, the Wind River Principal Meridian, the Ute Principal Meridian or the 6th Principal Meridian.
These two lines, the Baseline and the Principal Meridian are the fundamental axes and the foundation from which the PLSS was extended across the country. They are by no means abstract historical curiosities. By their monumentation these lines are a real physical presence today. And the Baselines and Principal Meridians are geographical lines, each as nearly a parallel of latitude and a meridian of longitude as the practical measurement technology of their day could achieve.
However, bear in mind that much of the early surveying in the PLSS was done with a solar compass and a linked chain. The discrepancies between the design and the reality of the monumented corners may be larger than would be expected if the work were done today with modern equipment. Despite that caveat the original work was remarkably good. Whether good or bad, however, there is no question it takes precedence over subsequent retracements or resurveys. The monuments set during the execution of the original survey, and the boundary lines they describe are correct and inviolable by law. It is an important principle of the Public Land Survey System and is mentioned, among other places in federal statute:
All the corners marked in the surveys returned by the Secretary of the Interior or such agency as he may designate, shall be established as the proper corners of the sections or subdivision of sections they were intended to designate. . .The boundary lines, actually run and marked in the surveys returned by the Secretary of the Interior or such agency as he may designate, shall be established as the proper boundary lines of the sections, or subdivisions, for which they were intended . . .
(BLM 2009: 13)
It is possible to think that since most of the public domain is no longer under the jurisdiction of the Federal Government the quoted statute does not necessarily apply to lands in private hands. However, the laws and courts in most states that were created from public domain follow the line that the rules established by Federal Statutes and elaborated in the various Manuals of Instructions will hold sway over the lands in state and private ownership under their jurisdiction.
At the intersection of the Principal Meridian and the Baseline there is an initial point, which is also represented by an actual monument. In fact, in the Manual of Instructions of 1902 not only stipulated that initial points should be set in conspicuous locations that are visible from a distance, but that they should be perpetuated by indestructible monuments like a copper bolt set in a rock ledge. Monuments perpetuate the initial points, most have been re-monumented, but the original monuments of 8 of the 37 initial points are still standing. The Baselines and Principal Meridians that extend in cardinal directions from them often, though not always, terminate at a state line. Once these axes were in place the next step was the creation of quadrangles.
Quadrangles
Figure 1.2
Quadrangles in the PLSS are large rectangular areas bounded by meridians of longitude and parallels of latitude. They are 24 miles on a side by current design, though that has not always been the dimension used. At each initial point a Principal Meridian on one side, a Baseline on another bound four such quadrangles and on the other two sides there is a guide meridian and a standard parallel, as illustrated in Figure 1.2. The lines around a quadrangle are known as standard lines.
A guide meridian was intended to follow a meridian of longitude. A standard parallel was intended to follow a parallel of latitude. And they both were established astronomically with corner monuments set every 40 chains, each half-mile, just as was done to create the Principal Meridian and the Baseline. Over a broad area of the PLSS there is just one Baseline and one Principal Meridian originating from one initial point, but there are many quadrangles built from them. And so these standard lines are numbered as you see in Figure 1.2. At a distance of 24 miles north from the Baseline there is the First Standard Parallel North, and 24 miles south from the Baseline there is the First Standard Parallel South. East from the Principal Meridian 24 miles there is the First Guide Meridian East, and to the west 24 miles there is the First Guide Meridian West. This logical system of numbering was and is carried through the whole region governed by a particular Principal Meridian and Baseline forming 24-mile quadrangles bounded by geographic, standard, lines.
The reason for this approach was explained in the Manual of Instructions of 1890,
Standard parallels shall be established at intervals every 24 miles, north and south of the base line, and guide meridians at intervals of every 24 miles east and west of the Principal Meridian; the object being to confine the errors resulting from the convergence of meridians, and inaccuracies in measurements, within the tracts of lands bounded by the lines so established.
(GLO 1890: 18)
Since the guide meridians were laid out following astronomically derived meridians of longitude they converged. Even though the First Guide Meridian East may have been 24 miles east of the Principal Meridian at the Baseline by the time it has run north for 24 miles and intersected the First Standard Parallel North that guide meridian was considerably closer to the Principal Meridian than when it started the trip. And convergence was unavoidable because the Principal Meridian and the First Guide Meridian, the Second Guide Meridian, the Third and so on were all meridians of longitude. Therefore, as described in the 1890 Manual, and illustrated in Figure 1.2, the guide meridians were not then and are not today continuous. They were designed to stop at each standard parallel, and the Baseline so they could be corrected back to their original 24-mile spacing.
At the south end of each of its segments a guide meridian was intended to be 24 miles from the Principal Meridian, or neighboring guide meridian. But at its north end, where it terminated at the standard parallel or Baseline, the spacing between meridians was inevitably less than 24 miles. It was less per the convergence of the meridians. As a consequence that segment of the guide meridian stopped there. A new segment was begun, but before that next segment of the guide meridian proceeded north for the next 24 miles it was shifted back to the correct spacing. It was corrected at the standard parallel to again be 24 miles from the Principal Meridian, or its neighboring guide meridian. In this way, it was ensured that the south end of the each segment of a guide meridian was then and is today 24 miles east or west from its neighboring guide meridian at its south end. But at the north end of each segment of a guide meridian was and is less than 24 miles from the next guide meridian because of convergence. And this is the reason that standard parallels are also known as correction lines. They are the lines at which guide meridians are corrected for convergence.
It is sensible then that the process of actually laying out guide meridians proceeded from the south to north. Corner monuments were set every 40 chains along the way, just as they had been done on the Principal Meridian and the Baseline. When the guide meridian finally intersected the standard parallel a closing corner monument was set. A closing corner was set where a surveyed boundary, here the guide meridian, intersected a previously established boundary, here the standard parallel or Baseline. Any excess or deficiency in the measurement that had accumulated in the work along the guide meridian was placed in the last half-mile preceding its intersection with the east-west standard line. So the last half-mile at the north end of a segment of a guide meridian may be more or it may be less than 40 chains. But more importantly the cardinal direction of the guide meridian was maintained all the way to its intersection with the standard parallel or Baseline. And therefore that intersection could not possibly fall on the already established corner monument on the parallel it was intersecting, because the guide meridian was no longer at the 24-mile spacing it had when it started.
Before the guide meridian was run a standard corner had been set on the standard parallel or Baseline 24 miles from the Principal Meridian or guide meridian to serve as a corner of that quadrangle. But as it turns out that standard corner could only be the correct corner of the quadrangle to the north, because when the guide meridian was closed on the standard parallel or Baseline the intersection of the two lines certainly fell somewhat west or east of the standard corner because of convergence. So in the end there was a standard corner and a closing corner at every corner of a quadrangle and they were some distance from each other. Well, with the exception of quadranglecorners set on the Principal Meridian, including the initial point. But in every other case there was a closing corner monument set. It was and is the corner for the quadrangles to the south. The corner monument for the quadrangle to the north will usuallybe a standard corner.
Figure 1.3
Townships
The quadrangle then became the framework enclosing the land from which 16 townships could be created. Townships are the unit of survey of the PLSS. A township is approximately 6 miles on a side and is designed to include 36 sections. The boundaries of a township are intended to follow meridians of longitude and latitudinal lines.
Please recall that as the standard lines around the quadrangle were run corner monuments were set at increments of half a mile, 40 chains. Some of those corner monuments were destined to become township corners. These were those set every 6 miles, 480 chains, along the standard lines, which are the boundaries of the quadrangle. From these corners the townships were established.
In the actual surveying of township the meridional, north-south, boundaries had precedence. They were surveyed from south to north through the 24-mile block of land, the quadrangle. These north-south township boundary lines were laid out along meridians of longitude as nearly as possible. As the meridional lines were laid out the corner monuments were set every 40 chains, every half-mile. On the other hand, the latitudinal boundaries of the township, the east-west lines, were first run on a trial or random line from east to west on most township lines. Random lines were also known as blank lines. Corner monuments were only set every 40 chains as the latitudinal line was corrected to a true line, usually west to east in these cases.
This random and true line method was used when corner monuments were in place at both ends of a boundary, but the boundary had not yet been actually connected by a surveyed line. It worked this way, a trial line, that is the random line, was created when the surveyor pushed his survey west from the township corner monument he had just established while he was surveying north up the meridian, say, at the northeast corner of a township. His next objective was to survey to the corner monument he knew he had already been set 6 miles away on the western boundary of the township, its northwest corner. As he proceeded toward it on the random line he set temporary points every 40 chains. When finally he intersected the western boundary of the township most likely he missed his objective corner. When that happened the distance, north or south that his random line missed the northwest corner was known as the falling. The falling was very instructive; it told the surveyor the distance he needed to correct his random line so it would actually connect the northwest and northeast corner monuments with a true latitudinal boundary. So, the surveyor would return east on the corrected line, this time from the northwest township corner to the northeast township corner. And along the way he would correct the temporary points he had set on the random line and set the actual corner monuments on the true line every 40 chains, except those on the westernmost half-mile.